It has become progressively more usual to provide disposable, absorbent articles of the aforesaid kind with elastication with the intention of improving the reliability of said articles against leakage and also to adapt the shape of such articles to the body shape of the wearer. This elastication often comprises elastic threads or filaments attached to a casing layer of the article and forming leg and waist elastic. It is also known to form waist elastic from thermoplastic material having a so-called elastic memory, instead of using elastic threads. The elastic properties of such material are enhanced, by stretching said material to the region of its plasticity range and thereby obtain a larger size. When the material is subsequently heated, the material shrinks to its original size and becomes elastic, so that it can be stretched resiliently to its earlier stretched state. Such memory materials afford technical advantages in manufacture in comparison with elastic threads, since it is necessary to hold such threads stretched during all the manufacturing stages of the article, whereas the elasticity of the memory material is obtained by heating the material after the article has been manufactured.
It is also known to use elastication for the purpose of imparting to the absorbent pad of an absorbent disposable article of the aforesaid kind a shape which will enable the article to be placed in position on the wearer more readily and which will improve the function of the article. Reference is made in this respect, for instance, to Swedish Patent Specification No. 8406071-4, which relates to such an article in which elastic threads are disposed in the form of a network, such as to form a pattern having curved parts, for instance curved leg elastic.
Furthermore, it is known from EP 0 098 983 to provide a diaper with resilient casing material surrounding the absorbent pad or body, such as to provide waist and leg elastic. In the case of this diaper, the resilient material is not pre-stretched, which means that it is necessary to produce all of the elastic force when putting on the article. Consequently, when using casing material of this kind it is not possible to deform the absorbent pad of a diaper in order to improve diaper function.
Despite long-term efforts by diaper manufacturers to provide improved shape-adaptability and improved leakage reliability with the aid of elastication, no manufacturer has successfully produced disposable, absorbent articles of the aforesaid kind which measure up to the hitherto best solution in these respects, namely diapers which are held on the child wearer with the aid of resilient pants provided with waist and leg elastication and particularly configured for the purpose intended.